Nearly a decade ago, Walsh’s return felt dramatic, and as genuinely surprising as the return, several years later, of his own hairline. Fast-forward to 2016, and Walsh’s reappointment feels like Cowell appearing on the deck of a beleaguered sea vessel and announcing: “I never thought I’d be saying this, but I think these deckchairs would look nicer further away from that iceberg.” While somewhere, in the distance, the backing tracks play on.

This week’s X Factor press release did its best to make the show’s return seem exciting. In the face of falling ratings, for instance, The X Factor was imaginatively billed as “the UK’s most talked about TV show”. The “legendary room auditions” are back, having previously been back, for one year only, in 2013. Back then, their return was as part of a back-to-basics idea, meaning that most basic of “outrageous” judges, Sharon Osbourne, also returned. She, too, is back in 2016, after saying talent shows were “boring”, complaining that “I’ve had it with people singing at me … I’ve had it watching people singing on TV”, publicly setting her sights on Strictly Come Dancing, and stating in 2015 that “I won’t come back with Simon Cowell”. Perhaps this no-nonsense woman of principle was swayed by a reported £2m fee, though it’s impossible to say.

Former judge Nicole Scherzinger is also back, leading Cowell to declare that this series is something of a “greatest hits” affair. As a former A&R man, Cowell knows what he’s talking about: greatest hits albums were usually deployed in an attempt to wring extra money out of a faded cash cow, make up for an act’s inability to come up with anything new, or – perhaps most tellingly, considering this year is the final X Factor of Cowell’s current deal with ITV – fulfil multi-album contracts.

But it’s Walsh’s return that is most noteworthy, and it does allow us a chance to ponder his unusual primetime TV career. It’s apt that Walsh seems supernaturally tied to a show that trades on its ability to make normal people famous enough to command three-figure sums for public appearances. Here’s a man who would quite happily admit that he has little on-screen flair for much more than blinking and holding the end of a pen, and he’s one of light entertainment’s biggest names.

What is it that makes Walsh such great TV? Developing a catchphrase out of an eyebrow-raising “little Lenny Henry” comment certainly shows bravado; occasionally banging a desk with his palms indicates an aptitude for showmanship. But while Scherzinger pulled out of her role in the Broadway revival of Cats in order to rejoin this year’s panel – a decision that prompted an apoplectic Lloyd Webber to complain he’d been made to “look like an absolute twot” – Walsh, who hasn’t created a successful band since 1998, is not apparently a busy man.

Walsh’s non-X Factor lifestyle is perhaps best outlined by the scenes depicted in, and indeed the very existence of, an ad he recorded last summer as part of an Irish chocolate bar promotion. Walsh is pictured letting himself into a spacious abode every bit as devoid of comfort as the properties routinely wheeled out during judges’ so-called houses. It looks as if Walsh has taken up work as an estate agent, and he certainly looks the part, but we then see that he is at home. His fridge, we’re shown, is home to one solitary onion. Has that lone vegetable been placed in the fridge as part of a Dorian Gray-style deal to ensure Walsh’s continued X Factor screentime? Again, it is impossible to say.

But we do see Walsh turning up the music on a cheap radio and, if you seek out this video, you’ll witness something you may once have considered impossible: the fact that a man’s hand can somehow appear unconvincing when turning a volume knob. As Yes Sir, I Can Boogie blares out, Walsh dances alone in purple socks, waving an egg whisk. It’s a scene so desperately bleak that it makes Dancer in the Dark look like You’ve Been Framed. Then the phone rings. “Yes of course I’ll be there,” Walsh agrees. “I’ll see you shortly.” He turns to camera: “I’m back!”

Just as Sharon Osbourne happily jettisons her principles for cash, so Walsh is happy to be portrayed, for cash, as a tragic clown with one onion in his fridge, waiting for Simon Cowell to call. But back in the real world it seems Cowell will always call, because Cowell believes Walsh is the improbable lifeforce at the heart of The X Factor.

Surplus to the requirements of the modern pop industry but apparently vital to the X Factor brand, Walsh is to The X Factor what Mark Hamill is to the Star Wars franchise. Away from The X Factor, Walsh may dance for chocolate money and appear on Who’s Doing the Dishes?, just as Hamill made do with voiceover work on Tom & Jerry: Shiver Me Whiskers. But in a fictional universe brought to life in a studio just outside London, their power is ultimate. Louis Walsh can joke that he needs The X Factor, because he knows that the opposite is, in fact, true. Whether Saturday-night TV viewers still need either is a question we can address in the autumn.